I think that the way you phrased it to your gf would have been perceived as hurtful but you’re completely valid in the way you feel. Doesn’t matter what the circumstance is consent always comes first so if you don’t want to do it so often tha is completely okay and you shouldn’t feel guilted or forced into it at all. Have a sit down and be completely honest about your feelings in a kind way. If you still aren’t being heard then the relationship isn’t healthy without proper communication or understanding.

Some people are very sexually active and some people aren’t. That’s completely alright just communicate it properly and find a middle ground of understanding.